Light Emitting Element Alignment Between Electrodes Using AC Waveforms

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Solution Overview

Problem

Current methods for aligning light emitting elements in display devices lack accuracy, which affects the performance and efficiency of these devices, particularly in high-temperature environments and in achieving precise alignment of inorganic light emitting diodes.

Innovation Solution

A method involving the application of asymmetric and symmetric AC voltages to form magnetic fields, deflecting and aligning light emitting elements such that conductive semiconductors are accurately positioned between electrodes, enhancing alignment accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional alignment methods are used for light emitting elements, then the manufacturing process is simple, but the alignment accuracy is insufficient

Engineering Contradiction:
Improvealignment accuracyVSAvoidalignment process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical alignment methods with an electric field-based alignment system. By applying AC voltage to electrode patterns, the invention creates electric fields that automatically align light emitting elements through dielectric forces, eliminating the need for complex mechanical positioning mechanisms and achieving high alignment accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention utilizes changes in electric field parameters (voltage frequency, amplitude, and waveform) to control the alignment process. By adjusting these parameters, the system can achieve different alignment states and optimize for specific element types, providing a flexible and accurate alignment solution without mechanical complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If organic material is used as fluorescent material, then the manufacturing process is simple, but the durability in high-temperature environments is reduced

Engineering Contradiction:
Improvedurability in high-temperature environmentsVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter from organic to inorganic fluorescent materials, fundamentally improving high-temperature durability. This material substitution enables the display device to operate reliably in high-temperature environments while the electric field alignment system maintains manufacturing simplicity through automated alignment processes.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If inorganic light emitting diodes are used, then the efficiency of blue light is improved, but the alignment precision requirements are increased

Engineering Contradiction:
Improveblue light efficiencyVSAvoidalignment precision
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent employs electric field-based alignment to meet the heightened precision requirements of inorganic LED manufacturing. The electric fields provide sub-micron alignment precision through controllable dielectric forces, enabling accurate positioning of inorganic light emitting elements without requiring complex mechanical precision systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly improves the accuracy of light emitting element alignment, leading to improved display device performance and durability, especially in high-temperature conditions.

Implementation Method 1

an asymmetric magnetic field can be formed by applying a first AC voltage having an asymmetric waveform to a second electrode, and thus light emitting elements may be deflected toward a first electrode

Methodology Applied
Scientific EffectElectric field: Electric Field

Implementation Method 2

a symmetric magnetic field can be formed by applying a second AC voltage having a symmetric waveform to the second electrode, and thus the light emitting elements deflected to the first electrode can be aligned toward the center between the first electrode and the second electrode

Methodology Applied
Scientific EffectElectric field: Electric Field

Data Source

PatentEP3855418B1Light emitting element alignment method and method for manufacturing display device by using same
Publication Date: 2024.03.27 SAMSUNG DISPLAY CO LTD
  • EP3855418B1 patent drawingFigure 1
  • EP3855418B1 patent drawingFigure 2
  • EP3855418B1 patent drawingFigure 3

AI summary

A method of aligning light emitting elements and a method of manufacturing a display device using the method of aligning light emitting elements are provided. The method of aligning light emitting elements, comprises: applying a ground voltage to a first electrode and applying a first AC voltage to a second electrode spaced apart from the first electrode; and applying a ground voltage to the first electrode and applying a second AC voltage to the second electrode, wherein the first AC voltage has an asymmetric waveform.